Thermostat (143°F/62°C) – Fits Johnson/Evinrude 60-300 HP V4/V6/V8 (Replaces 0434137, 0329766)

Thermostat (143°F/62°C) – Fits Johnson/Evinrude 60-300 HP V4/V6/V8 (Replaces 0434137, 0329766)

This thermostat is engineered for a wide range of Johnson/Evinrude outboard engines, including 3-cylinder models from 60-70 HP (1986–1992), V4 models from 120-140 HP (1985–1992), V6 models from 185-225 HP (1986–1992), and V8 models from 250-300 HP (1985–1993). It ensures proper engine temperature regulation for optimal performance and longevity.

As a direct replacement, this part interchanges with several OEM and aftermarket part numbers, offering a reliable fit for Johnson/Evinrude 0434137, 0329766, 0394409, and 0765580, as well as Sierra 18-3500, GLM 13170, and WSM 775-105.

• Installation Method: Direct replacement for a hassle-free installation.
• Operating Temperature: Precisely calibrated to open at 143°F (62°C).
• Package Contents: Includes one brass thermostat.

Part Number Cross-Reference

Use this table to confirm equivalent part numbers across OEM and aftermarket brands.

Compatible Engine Models

Confirm your engine model/year in the table below. For Johnson/Evinrude owners, here’s a guide to help you identify your engine’s serial/model: Johnson/Evinrude Serial Number Guide.

Technical Specifications

Package Contents

• 1 x Thermostat (Replaces 0329766/0394409/0434137/0765580)

Installation Guide

1. Ensure the engine is completely cool before starting.
2. Drain the engine coolant to a level below the thermostat housing.
3. Locate the thermostat housing and carefully remove the bolts securing it.
4. Note the orientation of the old thermostat before removing it from the housing.
5. Remove the old thermostat and gasket seal.
6. Thoroughly clean the mating surfaces of the housing and engine block to remove any old gasket material or residue.
7. Install the new thermostat, ensuring it is placed in the correct orientation.
8. Position the new gasket on the housing.
9. Reattach the thermostat housing and tighten the bolts to the manufacturer's recommended torque.
10. Refill the cooling system with the correct type and amount of coolant.
11. Start the engine and carefully inspect for any leaks around the housing.
12. Let the engine run until it reaches normal operating temperature to confirm the thermostat opens correctly.

Troubleshooting & FAQ

Q: How do I know if this thermostat fits my specific Johnson/Evinrude engine?
A: Check your engine's model, HP, and year against the "Compatible Engine Models" table. You can also cross-reference your existing part number with our list to ensure it's a direct replacement for numbers like 0434137 or 0329766.

Q: What are the signs of a failing thermostat?
A: Common signs include engine overheating, the engine taking too long to warm up, or erratic temperature gauge readings. A stuck-open thermostat will prevent the engine from reaching its optimal operating temperature, while a stuck-closed one will cause overheating.

Q: What is the operating temperature of this thermostat?
A: This thermostat is designed to open at 143°F (62°C) to regulate engine temperature.

Q: How often should I replace my outboard's thermostat?
A: It is recommended to inspect your thermostat annually and replace it every 200-300 hours or every 2-3 years, especially if operating in saltwater, to prevent cooling system issues.

Q: OEM vs. Aftermarket?
A: This listing is an aftermarket replacement part (not an OEM component). We build to OEM specifications using comparable-grade materials. Production is done in an ISO9002-certified facility, and each batch is inspected for consistent performance.

Q: How fast do you ship and how much does it cost?
A: We offer fast global shipping—typically 5–15 days worldwide—and standard shipping is free. Expedited options are available at checkout depending on your location.

Q: What is your warranty and return policy?
A: This product includes a 1-year warranty against manufacturing defects under normal use. If something goes wrong, contact our support team with your order details. Returns are accepted within our standard return window (unused & in original condition); please see our policy page or reach out for instructions.

Important Notes

• Verify that the product images and specifications match your original part. If discrepancies exist—even if your model is listed—do not proceed with the purchase.
• This product is an aftermarket replacement part and is not an OEM component.
• Professional installation is recommended to ensure safety and optimal performance.

Why Choose JLM MARINE?

• Quality Assured: As a trusted manufacturer for over 20 years, we supply top marine brands globally.
• Fast Global Shipping: Free delivery worldwide in 5–15 days.
• Direct from Manufacturer: Competitive pricing without compromising quality.